Compendium of the most significant studies with reference to properties, intake, effects.

Yanagiya M, Sato M, Ijiri N, Kobayashi K, Nagano M, Konoeda C, Kitano K, Nakajima J. Virtual-assisted lung mapping using dual staining with indocyanine green and indigo carmine enhanced marking detectability. J Thorac Dis. 2022 Apr;14(4):1061-1069. doi: 10.21037/jtd-21-1829. 

Abstract. We retrospectively reviewed the records of patients who underwent VAL-MAP DS. Twenty patients with 27 lesions underwent 72 VAL-MAP DS markings. We investigated the overall detectable marking rate, visible marking rate, successful resection rate, and complications.

Fabara AN, Fraaije MW. An overview of microbial indigo-forming enzymes. Appl Microbiol Biotechnol. 2020 Feb;104(3):925-933. doi: 10.1007/s00253-019-10292-5. 

Abstract. This mini-review provides an overview of the various microbial enzymes which are able to produce indigo and discusses the advantages and disadvantages of each biocatalytic system.

Roy PP, Shee J, Arsenault EA, Yoneda Y, Feuling K, Head-Gordon M, Fleming GR. Solvent Mediated Excited State Proton Transfer in Indigo Carmine. J Phys Chem Lett. 2020 May 21;11(10):4156-4162. doi: 10.1021/acs.jpclett.0c00946.

Abstract.  Here, the electronic excited state deactivation dynamics of indigo carmine (InC) is mapped by visible pump-infrared probe and two-dimensional electronic-vibrational (2DEV) spectroscopy and complemented by electronic structure calculations. 

Sista AK, Horowitz JM, Tapson VF, Rosenberg M, Elder MD, Schiro BJ, Dohad S, Amoroso NE, Dexter DJ, Loh CT, Leung DA, Bieneman BK, Perkowski PE, Chuang ML, Benenati JF; EXTRACT-PE Investigators. Indigo Aspiration System for Treatment of Pulmonary Embolism: Results of the EXTRACT-PE Trial. JACC Cardiovasc Interv. 2021 Feb 8;14(3):319-329. doi: 10.1016/j.jcin.2020.09.053.

Abstract. This study sought to prospectively evaluate the safety and efficacy of the Indigo aspiration system in submassive acute pulmonary embolism.

Christie RM. Why is indigo blue? Biotech Histochem. 2007 Apr;82(2):51-6. doi: 10.1080/00958970701267276.

Abstract. Although the color of indigo is strongly dependent on its environment, it is blue in most commonly encountered situations. Indigo's absorption at such long wavelengths for such a small molecule is unique, and I provide here an overview of the concepts advanced to account for this feature. A traditional valence-bond approach may be used to provide a reasonable qualitative explanation. A more rigorous, quantitative explanation is provided by molecular orbital methods of varying degrees of sophistication and several explanations have been proposed based on these models. Commonly, it is suggested that the important structural unit in determining color is based on the cross-conjugated "H-chromophore" concept. A second closely related explanation describes it as two symmetrically coupled merocyanine chains. Another proposal suggests that the basic chromophore may be interpreted as the aza analogue of two coupled anti aromatic-cyclopentadienyl ions. PiSYSTEM, a commercially available quantum mechanics program, has been used to provide a successful quantitative account of the colors of indigo and indirubin, a red isomer.

Mimura M, Alameddine RM, Korn BS, Kikkawa DO, Oku H, Sato B, Ikeda T. Endoscopic Evaluation of Lacrimal Mucosa With Indigo Carmine Stain. Ophthalmic Plast Reconstr Surg. 2020 Jan/Feb;36(1):49-54. doi: 10.1097/IOP.0000000000001457.

Abstract. Histological investigation in the use of indigo carmine for detection of mucosal pathology in lacrimal microendoscopy. To investigate the histopathological correlation of staining found on lacrimal microendoscopy.

Mielcarek J, Grobelny P, Osmałek T. Indigotine, azorubine, and cochineal red as photoprotectors of manidipine. Drug Dev Ind Pharm. 2010 Mar;36(3):302-6. doi: 10.1080/03639040903140597. 

Abstract. The protective influence of selected dyes on manidipine has been tested. The photodegradation of manidipine was performed according to the first version of the ICH Guideline for photostability testing. The solutions were illuminated by a high-pressure lamp HBO-200, and the methods used for evaluation of manidipine photodegradation were HPLC, HPLC-MS, and UV-vis spectrophotometry. Quantitative evaluation of photodegradation was made on the basis of the quantum yields of the processes with the use of Reinecke salt as a chemical actinometer.

Stasiak N, Kukuła-Koch W, Głowniak K. Modern industrial and pharmacological applications of indigo dye and its derivatives--a review. Acta Pol Pharm. 2014 Mar-Apr;71(2):215-21. 

Abstract. Plant sources, chemical properties, bioactivities, as well as the synthesis of indigo dye and its derivatives, are reviewed in this paper. These compounds were chosen because of their significant benefits and scope of application as both coloring agents in the textile industry and as pharmacologically active natural products. Their use in traditional chinese medicine (TCM) has directed the attention of European researchers and medical doctors alike. The preparation of indigoferous plants--Indigo naturalis is currently about to be introduced into the European Pharmacopoeia.

Kawanishi K, Maekita T, Ikeda Y, Furotani M, Tsuboi S, Kanno T, Niwa T, Nagaoka T, Tabata Y, Hatamaru K, Iguchi M, Kitano M. Oral indigo carmine for the detection of colon adenoma. Scand J Gastroenterol. 2021 Mar;56(3):351-355. doi: 10.1080/00365521.2020.1867897.

Abstract. Colonoscopy is currently considered the optimal method to detect colorectal neoplasia; however, some adenomas remain undetected. While indigo carmine staining with a dye-spray catheter has demonstrated promising results for reducing the miss rate, we investigated the oral indigo carmine method. The aim of this study was to determine whether oral indigo carmine intake before standard colonoscopy increases the adenoma (and adenocarcinoma) detection rate (ADR) or the mean number of adenomas per patient.